New answers tagged evolution
1
This competitive relationship often goes by the simple and intuitive name of sibling rivalry, and its closely related idea of parent-offspring conflict. While it may seem counter-intuitive for evolution, you must remember that while it's better for the parents to have multiple surviving chicks, it's better for the chick to have less siblings to compete with ...
2
While I do not know if there is a definitive answer to this question, I suspect that at least part of the answer can be found in the fact that animals typically have much more complex and delicate mechanical interactions in their bodies than plants.
From a mechanical perspective, plants are pretty simple. They move, but generally quite slowly and via very ...
1
Your fundamental mistake is this statement:
the purpose of an organism is to pass along its genes through reproduction
Evolution does not actually involve "purpose" in any way. Rather, it is just the observation that populations with traits that more reliably produce descendants end up with more descendants.
With regards to humans, being really smart ...
2
I assume by asking why, you are asking about the distal evolutionary causes, and not the molecular mechanisms that account for these things.
(Important disclaimer: these causes are difficult to be certain about; they require a fair amount of informed speculation.)
With that said: it is widely agreed upon in evolutionary biology that human males, as in ...
4
S Pr lists a number of reasons that might allow non-adaptive traits to spread. One other that's probably important in some populations is "allelic surfing".
If you imagine a smallish population that suddenly expands (say, starlings in the Americas, or humans in the past few thousand years), the original genes are going to expand no matter what - even ...
8
Good question. And good analysis. I have little to add! I'll simply provide my own list of thoughts to complement your ideas, which are not mutually exclusive.
The fact that it wasn't discarded during the course of the species'
evolution suggests it must have offered some benefit.
This statement is speculative. The key word here is suggests. i can ...
2
The simple answer is that the evolution of large, slowly reproducing organisms is not preferred: it is simply not selected against.
The key mistake in your thinking is this statement:
One of the main goals of living organisms is to reproduce
Most living organisms have no such goal, they simply take actions that have, historically, led to the ...
2
Short answer:
Many of the evolutionary developments in plants developed in the sporophyte life stage. Because increased fitness of these increasingly sporophyte-"dominant" plants would result in a greater survival and reproductive success, these plants became more dominant than the more-limited gametophyte-dominant early plants.
In other words, natural ...
1
This is for an animal, not a plant. But, when I was in school, the Peppered moth was used as an example of rapid evolution from the 19th century. Its white coat made it very noticeable against soot-stained surfaces so it had a rapid selection pressure to become black. If you can organise a trip with your kid to a natural history museum, you might be able to ...
1
Yes, in virtually every way. In terms of pairwise distances, measured in percentages, humans and coelacanth are closer to one-another than coelacanth would be to any ray-finned fish. In terms of individual genes, there would be genes that humans and coelacanth share with their common ancestor, but are not found in any ray-finned fish. Remember, humans are ...
4
Yes and no.
According to this paper, great apes and our ancestors had a life expectancy at birth of about 13 years (chimpanzees). Over a few million years of evolution, human life expectancy rose to >30 years in the 18th century. Industrialization and improved nutrition, hygiene and medicine resulted in a jump to >60 and now around 80 years in developed ...
-2
I would say that humans have not developed to live longer. There have been many harmful changes. One is that humans have lost the ability to produce their own Vitamin C.
Vitamin C
Hygeine has been a huge factor in humans living longer, especially drinking water being clean. For instance the American Public Health Association campaigned since the 1870's ...
0
Neither is "more advanced" than the other, they are separately evolved mechanisms to form a gut.
You may be misled by a human-centric view that treats humans and animals more humanlike as more advanced or "more evolved" than other animals but this is not true: all life has been evolving for the same length of time.
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Adjustment = a small alteration or movement made to achieve a desired fit, appearance, or result; the process of adapting or becoming used to a new situation (Google Dictionary).
Adjustment is a very general term; it doesn't mean anything specific in biology or other sciences and it can cover all the terms you've mentioned: adaptation, acclimatization and ...
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