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32

There are (at least) three important factors to consider here; evolution under selection requires genetic variation upon which to act, selection can act on covarying traits causing trade-offs, and adaptation also occurs in the predator. A lot of this is covered elsewhere on this site (including the effects of the other mechanisms of evolution), but little ...


17

There are two reasons for this: evolutionary trade-offs and coevolution (the "Red Queen hypothesis", as mentioned in the comment above by Luigi). Evolutionary trade-off describes situations where one trait cannot increase without a decrease in one or more others. Some hypothetical examples: longer legs may help run faster but past a certain point will ...


13

So earth is estimated to be around 4.5 billion years old, and life has existed for about 3.4-3.9 billion years of that, around >75% the time. For a little perspective, Homo sapiens have been around for up to ~250,000 years, just 0.00005% of the time earth has existed. In that time the earth has changed massively, early earth was pretty hostile, but that ...


12

The whole point of Darwin's theory was that transition from one species to another is extremely slow and gradual. There are plenty of quotes in "Origin of Species" stating this, and also affirming that there is no clear boundary between species and subspecies, or "races". Quotes from Origin of Species > Variation under Nature (Chapter 2) Quote 1 ...


10

Wagner does not propose any new theory. He uses the word innovation to mean evolutionary adaptations that manifest qualitatively different traits. In fact, he has himself not defined it properly in the mentioned book. This is what he has written about the term innovation: It may be difficult to define rigorously what an evolutionary innovation is ...


10

There are both costs and benefits to being able to run faster, both as a predator and as a prey animal. In short, maintaining the large muscles necessary to outrun a cheetah every time is metabolically expensive. So it isn't a matter of being able to always outrun a predator--it's a matter of how to optimally allocate precious resources either to ...


9

Lethal genes evolve simply because of random deleterious mutations and absence of strong selection. Recessive lethal genes Random mutations can make a gene product non-functional or reduce its activity. However, in diploid organisms the other fully-functional copy of the gene can compensate for the non-functional allele. Sometimes both the alleles can ...


8

The reason that chlorophyll is green is because it absorbs other colors of light such as red and blue, so in a way the green light is reflected out since the pigment does not absorb it. Because life might have been purple: It is possible that the very first life form to process light may have been purple colored. This would mean it was reflecting red ...


8

Short answer Before the RNA world, mineral surfaces may have facilitated the prebiotic containment and organization of biomolecules. Minerals are believed to have promoted the transition from a dilute chaotic prebiotic “soup” to highly ordered local domains rich in key biomolecules. Background As pointed out by others, the transition from a hereditary DNA ...


7

The flaw in his argument, from what I can see in your quotes, is to equate evolution to natural selection. Natural selection was never proposed to explain all evolution, nor how advantageous traits arise, but was proposed to explain how advantageous traits spread. Ultimately, why adaptation is so prevalent? The modern theory of evolution is so much more ...


6

It's a very simple answer. "Unhealthy" foods, for example potato chips, sugary drinks, and other fatty, cheesy or sugary edible items, have only been around a few hundred (at most) years. In prehistoric times (before agriculture, when the primary source of food was hunting and gathering), when food was scarce, fatty and sugary foods would be of great ...


5

An issue in the question that I will ignore You say Does the evolution head to some optimum that in future we will have only one species which will be superior to all other extinct form of life? Firstly, it is a little bit weirdly phrased. By "superior" I suppose you would refer to a species that could outcompete all the other. This sounds very ...


4

The methods that come immediately to mind are mostly related to next-generation sequencing. You can do deep sequencing on your sample, which is just increasing the coverage as much as possible to find rare events. You can do RNA-seq to look at the transcriptome, ChIP-seq to look at chromatin modifications, and single-cell sequencing (a form of deep ...


4

This is just loose terminology. By ‘lethal gene’ Dawkins means an essential gene with a mutation that renders it inactive. With a recessive gene, the one ‘good’ copy in the heterozygote provides enough gene-product to allow survival, in contrast to the situation in the homozygote where the total absence of gene-product is lethal. With a rare mutation, the ...


3

From Wikipedia: Anagenesis, also known as "phyletic transformation", is when the new morphospecies is a result of rapid evolution in the ancestral form without speciation taking place, such that there are no remaining other populations of the ancestor species and the species can be considered extinct. [...] Anagenesis is in contrast to the branching ...


3

While the attempt to consider this in a mathematical framework perhaps isn't so useful, it seems that the biological essence of your question is along the lines of: Does a Batesian mimic initially need to be initially quite similar in morphology to the different species which it evolves to mimic? The answer is no, morphology does not need to be ...


3

You can do without DNA, you need RNA to make proteins. Living organisms create and maintain a bubble that is very far removed from thermal equilibrium. So, you can speculate that at the origin of life, conditions existed where processes that are far from thermal equilibrium could still occur naturally without the support structures one finds inside living ...


3

What is new in his theory? What problems in evolutionary theory does it address? No major problems really. The problem he is claiming, or at least how it is portrayed, doesn't really exist. To borrow from my answer to your since closed question (see that answer for more): "Wagner appears to suggest that Darwin's theory relies on novel mutation ...


3

The short answer is NO. Here, very briefly (since it would take to much to properly analyze all the aspects of this topic), is why: First of all, the environment is constantly changing so there will be no such thing like 'the end of evolution'. Even if you try to stabilize the environment artificially (a lab setup) the organisms will continue to interact ...


2

Are kin selection and group selection the same thing? Yes and no. Yes: These days people tend to use the "direct fitness approach" (Taylor and Frank JTB 1996). It turns out that this is based on EXACTLY the same equation as is contextual analysis, which is the currently favored approach for measuring multilevel selection in natural populations ...


2

The concepts are very similar but there are a few differences. Firstly, fitness is usually applied to alleles or genotypes, reproductive success to individuals. Secondly (and partially as a consequence of this), fitness is an average or idealised/expected property across a population; but actual reproductive success per individual is stochastic. ...


2

Generally speaking, predators will always be faster than prey at a certain given level of biological (or technological) evolution. This, indeed, follows from the obvious observations: Herbivores consume food with low energy density. This means: a. Substantial percentage of their time is spent eating and processing food. b. Substantial fat and water ...


2

Short Answer- No, chances are negligible. Long Answer- Digestion is a chemical process which is mediated by enzymes. Enzymes are highly choosy molecules so that they only perform the work they're made for. In digestion, enzymes like proteases (for breaking down proteins), lipases (for breaking down lipids), amylases (for breaking down starch), DNAses (for ...


2

But cyanobacteria do not seem to use polysaccharides in the same way as plant cells do (building materials, for example) The Calvin-Benson cycle produces glucose which is the starting material for a lot of biosynthetic pathways including that of the nucleotides (ribose from the pentose-phosphate pathway). Glycolytic intermediates are also involved in ...


1

The main reason is that there really isn't any one "cold," but rather the word is used to describe many different infections that simply have the same symptoms. The reason for these same symptoms is that almost all of the symptoms that one experiences in a cold are actually the immune response to said infection. For instance, a fever is used to make the body ...


1

Predators always have to be much better hunters than the prey - they must eat every few days after all. But they can only get so good. Predator/prey population balance will tend to look like a competition where if the predators are too efficient they will kill off the prey. If that happens they start to starve to death. If the prey outrun the predators ...


1

Is there a difference? Yes, they are quite different things. What is group selection? Group selection is an view of evolution where selection acts at the level of the group, rather than the individual. It suggests that selection is mediated by fitness of the population, and leads to conclusions of things occurring for "the good of the species". It is ...


1

This example proves IMHO that migration is largely nature and not nurture: In the Netherlands, white storks were bred / reintroduced. A large part (about one third?) of the reintroduced birds do not migrate, but their offspring usually does migrate see. They couldn't have learned it from their parents, that's for sure.


1

Several proofs are given here (p. 9). My favorite comes from the genealogical argument: Consider the situation where there are $2N$ alleles: $A_1$, $A_2$, $A_3$ ... $A_{2N}$. By the genealogical argument, we may state that at $t = \infty$, all alleles at this locus will be direct descendants of one particular allele present at $t = 0$. Allelic variants at ...


1

I know of an example in development biology. Here is an example where noise in retinoic acid gradients is required for the boundaries in the developing hindbrain to sharpen. A related result is that the zebrafish hindbrain has a protein to modulate noise, but does not reduce the noise to zero. Together these results show that noise in the retinoic acid ...



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