As human mating with first and second cousins decreases, there seems to be a corresponding decline in the impact of recessive Mendelian diseases.
Consanguineous matings are an issue because the parents may both be expressing autosomal recessive genes from the same family lineage.
introduction of crack cocaine into this community
I am a little confused here, how does TB a disease that is spread by airborne droplets cause an outbreak that is traced back to crack cocaine?
genes produce antagonistic pleiotropy and tend to accumulate in the genome through evolutionary time
Would Alzheimer's disease be considered an example of antagonistic pleiotropy?
Human life histories are remarkably uniform, but with unique windows of vulnerability during which the environment affects genome expression
This is a very basic way to look at the entire concept of illness, I like it.
The harsh mountain environment may have buffered this group from the Europeans and their attendant diseases, the researchers say.
I wonder if the high altitude offered protection against other diseases and predators.
tracks the spread of humans from the top of Alaska to the tip of South America,
This is quite a large span of land with many different environments. It is very interesting to see who preferred to live in the cold areas versus warm.
Last, killifish re-peatedly evolved tolerance to polychlorinatedbiphenyls (PCBs) in urban polluted waters butnot in nonpolluted sites
Interestingly this relates quite a bit to neuro research projects going on at PSU looking at environmental toxicology of different drugs and the impact on fish and horseshoe crabs.
thatfragmenta-tion, founder effects, and human interventionresult in greater genetic drift in urban comparedwith nonurban habitats.
This, while very sad to think about, shows what capabilities the human race has compared to other species.
Fifty-five percent of people live in cities (1), with urbanareas comprising 3% of Earth’slandsurface(
3% really surprises me, I thought it would be much higher. As time goes on and if urbanization increases without much infrastructure or environmental change I do not want to see what living conditions will be like.
nor how this evolution may affect ecosystemsand human health.
This is interesting to think about during these times. Human health is quite fragile at the moment while ecosystems in many large cities are becoming much better. Having populations inside for a month or more has improved Venice's canals and China's air pollution.
Thus, the difficulty, which partly remains unsolved, is to understand the evolution of female (or male) preferences
It would be interesting to see how this began, what the first preferences were among different species and if those preferences have changed over time.
Darwin’s contributions are still surprisingly relevant to the modern study of sexual selection,
Quite interesting that observations and ideas created over 100 years ago are still relevant and taught in many classes.
Hence we can see that when a plant or animal is placed in a new country, among new competitors, the conditions of its life will generally be changed in an essential manner, although the climate may be exactly the same as in its former home. If its average numbers are to increase in its new home, we should have to modify it in a different way to what we should have had to do in its native country; for we should have to give it some advantage over a different set of competitors or enemies.
A climate can be perfect for an organism but if it does not fit into the specific environment it may struggle. A plant that needs lots of heat and little water due to may live well in deserts around the world but if put in a new desert with a plant that requires less water due to large roots everywhere the new plant may struggle getting its roots in the ground. Resulting in survival of the fittest.
In the case of every species, many different checks, acting at different periods of life, and during different seasons or years, probably come into play; some one check or some few being generally the most potent, but all will concur in determining the average number, or even the existence of the species
I sort of connect this to a keystone species. This one species has so many impacts on a specific niche that keeps everything working and thriving. If wolves were to become extinct then deer, rabbits, skunks would produce in abundance, this would create a shortage of mice, birds, and berries interfering with the rest of the environment.
Every being, which during its natural lifetime produces several eggs or seeds, must suffer destruction during some period of its life, and during some season or occasional year, otherwise, on the principle of geometrical increase, its numbers would quickly become so inordinately great that no country could support the product.
This is a very important sentence. It is really a game of chance whether you will struggle or thrive during a certain time. This creates a natural balance (natural selection) within the environment. Symbiotic relationships may be beneficial at times and being dependent may be beneficial at times. Everything is constantly changing, being adaptive is best.
Owing to this struggle, variations, however slight and from whatever cause proceeding, if they be in any degree profitable to the individuals of a species, in their infinitely complex relations to other organic beings and to their physical conditions of life, will tend to the preservation of such individuals, and will generally be inherited by the offspring.
This is talking about the importance of inherited traits. Something that is seen to be beneficial is usually "passed down" to the offspring believing it will be beneficial as well. This can create genetic variation due to different traits being useful in different environments.
Core information from field-collected specimens always includes species identity and place and time of collection, but increasingly, this information is being enriched with links to field notes and phenotypic (e.g., images), behavioral (e.g., sounds), and genomic data in a variety of databases
I understand why genomic data was not collected, but I wonder why phenotypic and behavioral analyses were not collected before. They are both relatively easy to observe and collect while genomic is a bit more advanced.
This approach is now being applied to eukaryotic model systems such as C. elegans and yeast
Are C. elegans and yeast the easiest model organisms to use for this study or was that just the organism of choice?
Does the evidence (e.g., blood, semen, or skin cells) at the crime scene tend to exonerate or implicate a suspect
While this has been going on for years I believe that it can invade personal privacy greatly. A closed criminal case is always better than an unresolved case but is it morally and ethically acceptable to unbury a deceased person to extract DNA samples?