Although evolutionary medicine requires further research to develop its distinctive viewpoint, it does provide a secure foundation for future developments in medicine.
I believe the evolutionary medicine approach is crucial to developing a vaccine that works for all four of the human effecting strains of Corona. We know quite a bit about its history with it being a derivative of SARS, so we must implement its evolutionary history into developing a vaccine.
Diseases characterized by neurodegeneration
Would this also include Multiple Sclerosis?
Epidemiologic investigation of these individuals showed that the introduction of crack cocaine into this community likely triggered the outbreak.
I believe in the case of COVID-19 the introduction of the virus is considerably more worrying. Corona is a zoonotic virus meaning the pathogens were passed form another animal to humans. To curb the spread among humans is difficult enough, let alone halting the spread among other afflicted mammals.
Evolutionary medicine previously uncovered the important concept of microbial trade-off between modes of transmission and evolution of virulence,27,28 and genomics showed how pathogens evolved virulence traits as they adopted horizontal modes of transmission.
This is especially relevant with our current global situation. Horizontal transmission is transmission via individuals of the same generation. This causes the rate of affliction to be considerably higher than viruses that are vertically transmitted.
This request was denied as the origin of the Spirit Cave Mummy was disputed, leading to a 20-year legal battle.
This is an interesting situation of morality vs. scientific advancement. The mummy was obviously extremely pertinent to knowledge of our origins, but it was also culturally significant to the Native Americans. Would the Native Americans have agreed to the DNA analysis if not for the 20-year legal battle?
This population likely didn’t spend too much time in North America, eventually finding their way into South America, while leaving no genetic trace of their journey—aside from this lone specimen in Lagoa Santa.
Given the genetic evidence from other populations during travel, its very interesting that this nomadic group remained traceless. I wonder if this was due to their geographic route and a lack of interaction with other populations, or was this a cultural element of strict breeding within the group?
They had a whole continent to themselves and they were travelling great distances at breathtaking speed.”
Was this within the era of domesticating animals for transport (such as horses), or does this predate that?
“That’s something we’ve suspected due to the archaeological findings, but it’s fascinating to have it confirmed by the genetics,”
Its fascinating to me how much new information modern technology is illuminating. Concepts that were previously theorized based on archaeological and fossil records can now be explored using genomics.
sometimes interbreeding with local populations, complicating the genetic—and historical—picture even further.
It would be interesting to learn the effect that this interbreeding had on the migrating Native American ancestors culturally. I can only imagine the cultural significance that occurred once two vastly different populations mingled. If there was a cultural impact, I wonder how this affected the population's overall survival (thus effecting evolution)? Were new tools and survival techniques obtained?
Knowledge of urban evolutionary phenomenamay be used to improve current environmentaland public health practices in cities or manipulateevolutionary dynamics of the species that live inor around our homes (97).
This is why I think permaculture i cities should be widely utilized. It not only promotes native species, but it would increase gene flow for pre-exiting inhabitants.
As with fragmentation, founder effectsmay also result in isolation between new urbanpopulations and their source populations.
When we think about speciation it is generally in the context of geographic isolation, genetic drift, natural selection, etc. It is interesting to attribute speciation to a founder effect in an area that seems so geographically small.
Even in more typicalcases, such as industrial air pollution that in-creases concentrations of carcinogenic hydro-carbons, mutation rates of repetitive DNA in birds(30) and mammals (31) may be elevated (Fig. 3A).
We see this in humans as well in instances such as lead exposure in Flint, Michigan. Various studies suggest that this exposure leads to a higher predisposition to develop mutations.
This occurs wheneverchanges in the environment act as a mutagen,increasing mutation rates in the germline orwithin somatic tissues that later differentiateinto reproductive tissue.
I believe mutation in urban areas is one of the few sources supporting genetic variation. Due to the condensed and fragmented "habitats", gene flow is heavily restricted.
This divergent selec-tion has led to adaptiveevolution in life history, morphology, physi-ology, behavior, and reproductive traits.
This concept can be seen first hand in cities where non-native raptors are present. Though cities are not their ideal habitat, many have adapted to eating the surrounding pests and residing in skyscrapers.
Now if we might assume that the males in the present class have lost some of that ardour which is usual for their sex, so that they no longer search eagerly for the females; or, if we might assume that females have become much more numerous than the males
I believe his second proposition is much more likely. I cannot think of an instance in which the males of a species would behave in a lackluster manor about finding a mate. The dispersing of their genes should be their primary concern. I very well could just not know of any examples, but it seems unlikely.
sexually
Again, I think this is incredibly interesting. It's hard to believe that an element of aesthetic appreciation does not exist within the display of flashy plumage or elaborate dances.
Thus, any treatment of sexual selection will be incomplete without a treatment of mate choice.
Preference is a huge component in the development of distinct phenotype. For example, female dung beetles tend to copulate with larger males, though this is not always black and white. There is a plethora of variables that effect a females choice, including her own morphology.
We are, however, here concerned only with that kind of selection, which I have called sexual selection. This depends on the advantage which certain individuals have over other individuals of the same sex and species, in exclusive relation to reproduction.
This seems as if Darwin primarily had intrasexual selection in mind. I am curious to know if the origin in intra/intersexual selection was developed from On the Origin of Species or if these terms were coined post publication.
should have all have been crossed with one supposed aboriginal stock.
This is interesting. I have heard a dorsal stripe considered a primitive marking. I have seen mustangs in colors ranging from buckskin to bay with dorsal stripes. I wonder why this coloration remained over thousands of years in only a handful of breeds?
the tendency to reversion and variability on the other hand, will in the course of time cease; and that the most abnormally developed organs may be made constant
Are there any examples of this? I'm sure there must be, though I think its peculiar that under a condition where variability is favorable, the organ or part will somehow become constant.
that natural selection is continually trying to economise in every part of the organisation.
Important
Whatever the cause may be of each slight difference between the offspring and their parents--and a cause for each must exist--we have reason to believe that it is the steady accumulation of beneficial differences which has given rise to all the more important modifications of structure in relation to the habits of each species.
Variation is dependent on both genetics as well as environment. The plasticity of the trait and individual is species dependent, and determines the classification of the trait.
disuse in weakening and diminishing organs
Appendix
are due to the several races of the pigeon having inherited from a common parent the same constitution and tendency to variation, when acted on by similar unknown influences.
Analogous variation occurs after an inherited trait becomes popularized between species under similar circumstances.
sexual selection, which is less rigid in its action than ordinary selection, as it does not entail death, but only gives fewer offspring to the less favoured males.
Sexual selection does not guarantee death. The change in characteristics by favorability occurs slowly over time.
what is meant: if in a large genus of plants some species had blue flowers and some had red, the colour would be only a specific character, and no one would be surprised at one of the blue species varying into red, or conversely; but if all the species had blue flowers, the colour would become a generic character, and its variation would be a more unusual circumstance.
The abundance of a characteristic determines whether or not that trait is specific or general.
These slightly varying organisms are interesting in as far as they present characters analogous to those possessed by the species which are confined to similar conditions.
Species under similar conditions possess similar characteristics.
In the latter case the organisation seems to become plastic, and we have much fluctuating variability
Changed conditions via reproductive system tend to be more plastic.
But the fact of variations and monstrosities occurring much more frequently under domestication than under nature
Important point to hit!
"...including discovering genomic signatures underlying the evolution of prezygotic reproductive isolation, and describing how hybridization, contact between incipient species, genome reorganization, and genome duplication, affect speciation."
I have always taken an interest in the geographical and social methods of speciation, but I think it would be fascinating to learn about the genomic processes that lead to it. I hope we touch on these mechanisms at some point during the semester.
"The flood of data in all areas of evolutionary biology poses important theoretical challenges: new kinds of theory are sometimes required to make sense of new kinds of data."
This is precisely why integrative biology is so integral. The union of all the biological fields would allow for a plethora of different approaches and perspectives.
"In the following sections, we briefly highlight some key applications of evolutionary biology, provide examples of emerging research areas, and identify infrastructure and training needs."
(For some reason the page is no longer allowing me to annotate so I made this a page note.)
I believe this concept is integral to the advancement of all fields of biological sciences. I think this thought process also heavily relates to integrative biology. The authors speak about how they gather groups of scientists to look for opportunity across the disciplines. This concept gives a collaborative and open minded approach to problem solving within the scientific community. I am glad the shift toward integrative biology is continuing, though I hope Plymouth would put together seminars across the biology majors where we could have open discussions about real world problems.
Though Dobzhansky's statement is sometimes dismissed by biologists in other fields as self-promotion, recent advances in many areas of biology have shown it to be prophetic.
While I understand how this statement could be viewed as self-promotional, I agree with Dobzhansky's sentiment. In order to fully comprehend any one element of biology, the evolutionary lens must be utilized. This not only holds true for historical and present discoveries, but also interpreting future events. For example, in order to speculate the future ecology of a given area or the morphology of a given species, the context of evolution must be examined. The future cannot be predicted without knowledge of the past.
Novel conditions—those notpreviously experienced during the evolution of a particular developmental switch—may resultin the inability to respond adaptively (Figure 2a). Alternatively, new environments may inducea range of maladaptive and potentially adaptive responses through the “spreading” of reactionnorms and release of cryptic genetic variation
This is another good example of a limit to phenotypic plasticity. This states that novel conditions have the ability to prevent an adaptive response. This is due to being developed through a threshold for phenotypic switch. With conditions that have been experienced during evolution there are phenotypes present that have been adapted to a wide range of environments. This is particularly concerning because extremely novel environments will continue to be very difficult to adapt to.
Overall, we argue that the mechanisms of plasticity likely to produce a highly adaptive response toa novel environment are also the most costly, resulting in shifts to relatively slower life historiesand less pronounced evolutionary responses at the population level.
This is a perfect example of a hypothesized limit to plasticity. The authors are proposing that with a higher adaptive response to environmental shifts comes a slower life history and population level response. When I think about phenotype plasticity I think of an inherently good survival mechanism, often overlooking the implications that such a response can entail. A certain level of fitness is required in order for plastic responses to take place, which in turn limits the overall ability for a population level plastic response. The implications of a plastic response are not always positive.
Urban and agriculturaldevelopment in once-pristine habitats, the introduction of new toxins or highly competitive inva-sive species, and increasingly severe climatic shifts all pose unique challenges for native populations
These factors are pertinent to the limit and extent of plasticity because they are all environmental factors that can severely affect the survival of wild populations. These factors also have the potential to shift dramatically over time, forcing the relative plasticity of an individual to adapt with it. As urbanization and climactic shifts increase in frequency, so will the level of plasticity found among wild species. Studies such as the ones we are proposing now are extremely important for predicting how these environmental changes will affect plasticity.
The degree of development of the sensory and motor capabilities of the brain in neonates during strict lactation is remarkable.
I have always heard that breast-feeding a child is better for them than bottle feeding, though I had never really understood why. I suppose people are speaking on the beneficial microbes that are present in breast milk, or even the microbes that can be transmitted from the mothers epithelium. I am eager to look into studies comparing the immune health of a child that was breast-fed vs. bottle fed.
Milk also includes urea and oxalate, two end-products of human metab-olism. Why would nature include such indigestible molecules in the diet of young mammals?
This makes me wonder if all mammalian breast milk contains generally the same beneficial microbes? If not, I wonder if there is an affect on the gut microbiota of humans that consume cows milk vs. that of a vegans. I'm sure the overall makeup of the gut microbiota would be vastly different, but I wonder if that plays a role in other micro-scale functions.
shared for excretion and reproduction. Placental mammals evolved separate canals for reproduction (vagina), excretion of faeces (anus) and urine (urethra), and the birth canal is always adjacent to the rectum (but not the urethra), providing an efficient mechanism for intergenerational transmission of both vaginal and gut microbes.
Are the authors suggesting that this aspect of mammalian evolution was in part to reduce the risk of infection that comes with a single canal? It certainly makes sense given that prolonged labour increases the risk for infection. I wonder if there is a correlation between longer the exposure to maternal vaginal and fecal microbes and the overall immune health of the infant.
The gut25 and vaginal26 maternal microbiota change with gestation, and whether or not these changes have adaptive value for the mother or baby is still unknown. It has been suggested that they allow the fetus to derive energy from the mother’s blood, more efficiently,25 or that butyrate-producing bacteria may sustain gut epithelial functions and promote immune tolerance in the mother
This would be a fascinating concept of phenotypic plasticity to explore. Perhaps further comparisons of maternal and non-maternal microbiota during gestation would lead to new information on its potential adaptive value. I believe that it must yield a certain level of adaptive value, whether that is effieciency of nutrient uptake or an immune protective "barrier". It would also be facinating to know what triggers this colony-wide microbiota change during gestation. Perhaps an increase in estrogen or progesterone plays a role in signaling.
Althoughmorestudiesareneeded,manylinesofevidencestronglysupporttheideathatepigeneticdi-versity(attheintraspecificlevel)isarelevantfacetofbiodiversityforunderstandingandpredictingthefunctioningofecosystemsandthatsuchlevelofdiversityneedstobeintegratedintomanagementpolicy.
With this knowledge more studies and experiments can be conducted to truly understand the relevance of epigenetics and biodiversity, and their symbiosis. Not only does this encourage integrative biology for field research, this also includes environmental law for conservation and sustainability efforts.
Akeyaspectofbiodiversityconservationconcernsthepotentialpervasiveinfluenceofhumansocietiesonbiodiversity.
This is an extremely pertinent concept. This not only encompassed the importance of epigenetic influence on biodiversity, but it also includes the importance of these factors in relation to human society. As humans we are hugely reliant on this natural world that we largely take for granted. Epigenetics can allow us to optimize crop yields, which in turn influences the food industry and medicinal development. By maximizing ecosytem biodiversity, we can increase overall plant productivity. This gives us a new and improved model for agriculture.
Alternatively,environmentalchangescanpotentiallyinducespontaneousandrandommodificationinDNAmethylationpatternspotentiallyresultinginthebroadeningofphenotypicvaluesaroundtheoriginalmeanphenotypewithinpopulations(i.e.correspond-ingtothestochasticdevelopmentalphenotypevariation;i.e.SPV;Angersetal.,2010;Vogt,201
How common are these spontaneous and random modification in methylation patterns? Does this result in a more broad mean phenotype than that of standard changes in methylation patterns due to changing environment?
Wewillthenoutlinewaysthatepigenetictoolsshould–andcan–bepracticallyimplementedinbiodiversityconservation.
This is incredibly exciting news for conservation efforts across the globe. It is certainly a new concept to approach conservation through the lens of epigenetics. This concept promotes an integrative and fresh approach to problems that we have been facing for countless years. Though it seems as if the hardest part of conservation on any front is legislative support, perhaps new methods will elicit an overall change in mentality as well as new discoveries.
Crassulacean acid metabolism (CAM) is a strategy tomaintain photosynthesis under conditions of closed sto-mata. Owing to its release from carboxylic acids formedduring the night, CO2in CAM plants can be converted intosugar by the Calvin cycle despite the gas exchange isprevented (Cushman and Bohnert1999). Photosynthesis ofthe CAM type is, however, not uniform over the day, butundergoes diurnal changes, which can be assigned to fourdistinct phases with respect to the predominant enzymeactive in carboxylation (Osmond1978; Winter and Smith1996; Borland and Taybi2004; Winter and Holtum2007).While at night fixation of CO2by PEPC leads to accu-mulation of carboxylic acids (phase I), at the onset of theday (phase II) stomata temporarily open and a transitionfrom carboxylation by PEPC to carboxylation mediated byRubisco occurs. Decarboxylation of carboxylic acids inconcert with the fixation of CO2by Rubisco during mosttime of the day (phase III) is followed by a transition to C3photosynthesis towards the end of the day when resourcesof accumulated CO2are depleted (phase IV). Mesophyllcells of CAM plants are subjected to considerable fluctu-ations of the internal CO2level. During phases I and II,they have a low level of CO2and high acidification, inphase III CO2concentration is increased and accompaniedby an increased level of oxygen, and then the level of CO2is decreased again in phase IV.
This paragraph informs the reader on the mechanisms of Crassulacean acid metabolism and when it is put into effect. To do this, the writers also use primary examples of studies that have observed the "when" and "how" of CAM plants. They also lay out the mechanisms by which CAM maintains photosynthesis.
However, despite the big data now available, we still don't understand how organisms construct phenotypes from genotypes
This has certainly become apparent to me in taking both Genetics and Eco Devo at the same time. I believe its fascinating to compare and contrast the differences between the relatively set in stone mechanisms of genetic inheritance vs the largely unexplored realm of epigenetic mechanisms and its relation to phenotypes. The sheer amount of variability in phenotypic expression relating to environment is immense and truly interesting to explore.
Experimentally silencing a DNA methyltransferase in honey bees altered larval development, such that they were more likely to develop into queens (Kucharski et al. 2008). Thus, differential methylation may underlie many of the differences between queens and workers.
Mechanism isn’t a “silver bullet” to explain variation because phenotypic traits are not necessarily going to be presented with epigenetic modifications. The relationship between mechanism and variation is not direct, meaning the correlation is loose and contains variability in and of itself. For example, an organism can be more likely to develop a certain phenotype, but not positively going to. There are no direct patterns to this relationship.
The model clearly indicates that genetic and non-Benetic inheritance mechanisms can interact, and if there is an association between the
Epigenetic modifications are generally considered non-genetic because they tend to not be as “cut and dry” as DNA mutations. These modifications can elicit phenotypes without affecting the genetic makeup of an organism, often resulting in an outcome that could otherwise not be achieved from genetic variation alone. I believe the main distinction between epigenetics and mechanisms of genetic variation is that epigenetics is highly unpredictable. With the methods of karyotyping and gene sequencing we have today, it is far easier to predict the genetic makeup of an organism, rather than the result of epigenetic modifications.
the kindergartner, learning about the plants and animals that live in the schoolyard pond, a rice paddy, or a garden near home, can participate in a discussion of the biology of the organisms and their interactions with one another, the effects of climate, the social dimensions of food and water supply and desiccation, and the aesthetics of a calling frog's song or a beautiful stand of plants.
After working at an environmental education camp for the duration of my summer I can certainly attest to the importance of making those visually tangible scientific connections at a young age. Something as seemingly minuscule as sweep netting in a meadow can initiate a discussion of biodiversity.
that it at once advances not only an individual's central disciplines but also other fields; it provides for the generation of new hypotheses, techniques, and ideas; and it establishes environments that promote the interactions that facilitate new syntheses and ideas.
In addition to these advantages, integrative research may also spark up a passion that was previously not realized and may have remained undiscovered. Integrative research not only benefits the advancement of various scientific fields, but also the blossoming of bright minds and the potential for a life of deeply enjoying your career.