New answers tagged evolution
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The general theory is RNA came first, then DNA. Both are able to replicate with simple changes in temperature (see polymerase chain reaction). So if we imagine a world with nucleotides making RNA, the idea is the survival of the fittest RNA. RNA for example that also had enzymatic activity was "fitter" than RNA that did not. Then go further down the line ...
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In certain cases, yes medical intervention has delayed NATURAL SELECTION, but not evolution. We are adapting in the process of developing new drugs, which is one of the evolutionary strategies. However, genomic evolution is retarded by retardation of natural selection. But again, Genomic changes can be triggered by medicine (both in the context of side ...
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Not at all.
Mutations accumulate independent of medical progress. In fact harmful mutations which would otherwise cause an individual to die can now be "cured" thus if anything increasing the gene pool.
Typically medical progress extends our lives when we are much older, thus we have already passed mutations on to our children before a bottleneck in ...
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You are correct that the reason is similar to that of convergent evolution of the eye.
Both snakes and legless lizards are lizards (Squamata) that have lost their legs. However they have done so entirely separately much as octopus and human eyes have evolved entirely separately. An easier analogy is between whales and sea cows. Both are legless mammals but ...
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Here are some off the top of my head.
The height an animal can jump depends on the muscle cross-sectional area ($l^2$) and its mass ($l^3$). Mass grows faster with body size ($l$) so small animals can therefore jump higher relative to their body size ($l$) than large animals. Very similar scaling exists for strength of limbs vs. mass, ability to fly vs. ...
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Good question. Evolution will and does continue. Mass extinctions have happened in the past and in fact we are the product and beneficiaries of that process; when niches open up from extinctions, other species just move in and take over, eventually they will adapt to take the place of those who have left. Of course that's a useful perspective since it ...
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Here is a possible answer given by this paper:
http://www.ncbi.nlm.nih.gov/pubmed/16794952
or
http://www.math.unl.edu/~bdeng1/Papers/DengDNAreplication.pdf
It gives a Darwinian explanation to the question. It approaches the problem from Claude Shannon's theory for communication. It treats DNA replication conceptually and mathematically the same as a data ...
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Pheomelanine,has it normal function in transforming radiant heat to energy but can't protect its host from ultra violent wave from the sun as ultra violent waves will distroy melanin cells.
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From Wikipedia:
Sloths go to the ground to urinate and defecate about once a week, digging a hole and covering it afterwards. They go to the same spot each time and are vulnerable to predation while doing so. The reason for this risky behaviour is unknown, although some believe that it is to avoid making noise while defecating from up high that would ...
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The man in China had both chromosomes 15 split and attached onto both chromosomes 14. If a male with 44 chromosomes wants to have children with a female with 46 chromosomes, this will not work. He won't be able to have viable offspring. During mitoses, he will have 22 chromatids and she will have 23. They will not match up and therefore no viable offspring. ...
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