I don’t think biological evolution is perceptible over the timescales you’re discussing. Speciation works over very large time scales. We’re genetically identical with h. Sapiens that lived 50,000 years ago. I recall reading recently that blue eyes and red hair are both relatively recent genetic developments, but the timescales involved again were 50-70000 years. And also, abilities are not necessarily specified by genes, they can be the result of epigenetic influences. And finally, not a philosophical question.

Sorry for the delay is elaborating.

This is a philosophical question in that it relates to what a human is and the mathematics of biology

Birds and rabbits are often pointed out as an example of speciation since some groups of these can only now only reproduce within their group. It would be an example of evolution of from there they developed totally new skills. If a species is defined as that which cannot reproduce outside ones species, the first of a species must be lucky enough to have a mate that evolved like them. This makes evolution-s mathematics very confusing for me. I'm not seeing how it works in the sense of the game Life for example (The one invented by John Conway)

I don't have a problem with nominalism. Some think that it is necessary t o posit quasi-spiritual natures in living things. I'm ok calling a female a female or a male a male even without reference to so-called "natures". So evolution makes philosophical sense to me. If someone disagrees, please join in. However, what i ve been reading over the past day about when a species is made is not adding up in my head. So sorry again for not getting back to this sooner. This complements questions I've asked about pattern formation in the past

Mutation is a big part of the theory of evolution. Whether we like it or not, selectively breeding a being with another creates a being that may have traits alien to the parents. These are usually very subtle mutations but can lead to significant changes through the concept of chaos itself. The conditions of birth have a major impact too. As does the time and place if you are into astrology. The story goes that Nicola Tesla was born on the night of an intense electrical storm,

Yes, that "species" is not precisely defined I think is the answer to my questions. If it was a static feature I don't see how evolution could work. With birds and rabbits which can't mate with other birds and rabbits anymore, I would like to see these groups go on and evolve another set of animals that cannot mate with the original evolved groups we have now

Dr. Grande has an episode on Tesla. He is always a little harse but that is his job I guess. He provides some interesting biographical facts within a framework. You can view it on you-tube

If a species is defined as that which cannot reproduce outside ones species, the first of a species must be lucky enough to have a mate that evolved like them. — Gregory

Interbreeding populations would drift slowly away form each other on the basis of some kind of environmental separation prior to genetic separation. Any genetic differences between two populations less frequently interacting that affect fitness might help to accelerate speciation over time, probably. It (speciation) takes a village (population) and time, if asexual reproduction isn't in play.

Polar bears can breed with brown bears to produce fertile grizzly–polar bear hybrids;[4][30] rather than indicating that they have only recently diverged, the new evidence suggests more frequent mating has continued over a longer period of time, and thus the two bears remain genetically similar.[29] However, because neither species can survive long in the other's ecological niche, and because they have different morphology, metabolism, social and feeding behaviours, and other phenotypic characteristics, the two bears are generally classified as separate species.[31] — Wikipedia: Polar Bear

Say we have a group of closely similar humans. One evolves a new ability and mates with someone who complements this through reproduction of a child that is especially adapt at the new skill. Who does this child mate with? — Gregory

A mutation could happen to a dominant gene or a recessive gene. Either way, the mutant doesn't have to mate with a fellow mutant to pass on the change.

Here's an example from the BBC:

Scientists have discovered the specific mutation that famously turned moths black during the Industrial Revolution. In an iconic evolutionary case study, a black form of the peppered moth rapidly took over in industrial parts of the UK during the 1800s, as soot blackened the tree trunks and walls of its habitat.

Why would evolving into a black moth have helped the previously light colored moth? They were less conspicuous, less noticeable to birds. The birds ate more of the lighter colored moths, increasing the percentage of moths that were darker. Over time, there weren't any more light-colored breeding moths.

So, now what? As the air becomes less soot-filled and bark becomes lighter, dark colored moths will be at a disadvantage--the birds will pick them off more frequently. Two things may happen: the moths may lighten up, or they could go extinct (all eaten). ON the other hand, the birds may go extinct or shift their feeding habits, and it won't make any difference what color the moths are. They may stay dark.

Because of climate warming, migrating bird arrivals and insect hatching times are no longer synchronized in the same way they were 100 years ago. Birds may adapt, or they may have more difficulty feeding their chicks. Time will tell.

Don't forget "the regression to the mean", also called "regression to mediocrity". Two stupid people who mate are more likely to produce an average child rather than an even dumber blockhead (this is a great mercy). Two geniuses are more likely to produce an average child than an incredibly brilliant one. On the other hand two geniuses may produce an idiot and two idiots might produce a genius--probably not, but it's possible.

One of the problems in tracking the regression to mediocrity is that people frequently have an unwholesome influence on their children, turning otherwise bright offspring into imbeciles. Were they cretins to start with, or did their parents degrade them into deep stupidity? Very hard to tell. You'd have to be a live-in observer for years, carefully charting the dismal progress.

Sometimes relatives or neighbors witness the process of idiot-making carried out by parents who really should never have been allowed on an unchaperoned date in the first place.

https://www.bbc.co.uk/news/science-environment-36424768

I am again surprised by some of the misconceptions in this debate.

Humanity has only identified one mechanism for Evolution in the entire universe - the living cell.
It does this (evolves) by deploying three key sub-mechanisms:

1 - it maintains a template, (DNA), whose sequence can be broken on one or both strands up to 10,000 times a day. The repair of the DNA sequence by a handful of enzyme molecules normally produces a perfect re-construction, but occasionally leads to a mistake in one among 1million genes in the DNA sequence. This is known as a mutation.

An incorrect (mutated) gene may lead to a cancer in a developed being, but its true effect will only be realised if the mistake occurs in, or is incorporated into, the DNA of an egg or sperm prior to fertilisation.

As Darwin and Dawkins explain, if the changed genetic sequence still produces a viable embryo, that entity will develop into a full living being that is either helped or hindered by the change. Such genetic changes will not be transmitted as frequently if the individual resulting from them has a disadvantage, while those beings who gain advantage by such a change will survive longer and therefore spread that gene more prolifically - enabling it to become established in the population.

The reason why different species cannot normally reproduce is that too many of their genetic sequences are incompatible. However science has shown that where there is compatibility then successful mating is possible. Horse & Donkey produce Mules, but Mules will not be able to reproduce until such time as the necessary compatible genes might arise in them. One day they might at which time a new species will come into existence. Ditto Tigons, etc. To prove the point, scientists have transferred fluorescent and other genes into species that wouldn't normally have them - because those genes do not affect the reproductive abilities of the new creatures.

Genetic mixing by living beings with different genetic characteristics does not represent a new mutation, but a spreading of one that has already been shown to be viable within a living being.

2 - living cells replicate their genetic sequences in order to reproduce both proteins/rna and indeed entire new living cells.

3 - they metabolise in order to maintain a source of energy and component supplies for them to perform the earlier tasks (1 & 2 above).



The mystery, therefore, is how is how the complexity of the first living cell could be achieved before the only mechanisms that is able to manufacture it - another living cell.

As Finipolscie says - Evolution is a process of change; it is not a process of start.

The mystery, therefore, is how the complexity of the first living cell could be achieved before the only mechanisms that is able to manufacture it - another living cell. — Gary Enfield

Some fun facts along these lines...

Despite centrality of sunlight-requiring photosynthesis to the biosphere, it was found that prokaryotic organisms survive in many climes, wherever energy can be harnessed by chemistry. Theories were formulated that considered the possibility of extremophile prokaryotes as the first lifeforms, a likely option considering turbulent conditions of an Earth that, 3.8 billion years ago, was still in volcanic apoplexy. It became common currency that early Earth was profuse in nitrogen and carbon dioxide gas as well as water, with paltry amounts of ammonia and methane, conditions prevailing in the interface between the atmosphere and Earth’s surface, but due to chaos induced by tectonic shifts and magma emissions, it seemed likely that life would have burgeoned in more stable deep ocean environments, though an energy source had to be available.

This led scientists to deep sea hydrothermal vents surrounded by teeming populations of single-celled life. Near boiling ocean water heated by the molten mantle beneath Earth’s crust froths around fissures that inject hot gas as well as simple subunits of macromolecules such as amino acids and other carbon compounds into nearby rock, eroding microscopic pores within their bulk. Chemicals circulate in and around these tiny chambers that act like nodes between wormlike tunnels connecting this collective chemistry to the outer ocean. It is postulated that dissolved gases such as carbon dioxide, hydrogen and nitrogen, as well as organic molecules and proton gradients from hydrogen atoms stripped of electrons all subsist in the supercharged environment, conditions that may be sufficient to produce a metabolic cycle without the presence of membranes, as networks of linked pores could be the total requisite structure, functioning like a congregate of cell walls. Metal ore surfaces exposed within the chambers may catalyze energy transfer, acting the role of primitive enzyme. It is an intriguing model, one that seems to explain what could be bacterial descendants living in droves nearby, and scientists recently committed to testing it.

An experiment was designed that placed a solid clay brick with microscopic pores and channels in a sealed cylinder of aqueous solution. A tube pumped heated flow of water through the clay in such a way that circulation was achieved, and further tubing was assembled to introduce gases and organic molecules to the solution in a concoction that mimicked postulated conditions of hydrothermal vents with high fidelity. Scientists planned to set the apparatus in motion and determine whether larger molecules can be formed. Efforts such as this may disclose much about how life may have irrupted into existence.

It is not hard to imagine a sort of membranous biofilm adhering to interiors of the rock, becoming studded with as well as inhabited by macromolecular clusters conjuncted to the nutrient rich cycle, then differentiating into primitive cells that expanded in range, complexity and diversity as the first prokaryotic lifeforms. Each evolutionary step is improbable on its own, but metabolic self-sufficiency together with mutational self-replication only had to materialize once or rarely, and billions of years of naturalistic trial and error in prokaryotic time is like a macrocosm of the universe.

Thanks guys.

The position of the anti-Darwin crowd is that genes cannot be combined efficiently any which way we like. They think each "kind" has a common ancestor pair and that getting from, say, a fish to a snake through evolution is impossible because the intermediate states are not feasible. They disagree with Dawkins on the number of genetic combinations that can function in Earth's environment
They go on to argue that the cell cannot arise from natural causes and this must be a miracle

@Wayfarer if interested. Evolution from D'Arcy Wentworth Thompson's (1860 - 1948) point of view isn't anything to be surprised by. The basic body plan is identical in all organisms, at least within a given phylum if I'm correct. The variations in bodies we observe, sometimes so extreme that we completely fail to see the similarity, are simply geometric transformations which may involve some topological elements on the basic baupläne common to a given phylum. The bottom line - some might say - is that we're all just glorified tubes.

See here

That takes care of the physical aspect of evolution. Coming to biochemistry, it's an open secret that all living organisms, even across phyla, have similar, even identical, biochemical pathways.

So, there's not much to evolution - the variety we see in the living world doesn't require too much "work" i.e. random mutations in DNA can easily handle the evolution of species because, at the end of the day, what's happening is existing species are being, how shall I put it, deformed/disfigured i.e. it should be much, much harder to preserve a species' characteristics than to alter it (to form new species).





We're just deformed chimps. :lol:

Gregory

I don't think it is helpful to designate valid queries about the limits of Darwin's theories as being religious creationism.

Valid questions are valid questions, regardless of who they come from. (That said, I haven't seen many sensible arguments coming from the creationist camp - though I give one example below).

However the point about the origin of the first cell is valid. It was originally ridiculed by so-called scientists in the 1950s- 1980s, but then the scientific community realised that this was a valid point and that while an evolutionary approach seems to be necessary to form something as complex as the fist living cell, there was no alternate mechanism to do this.

This is what sparked the whole field of Abiogenesis - which over the course of decades has spectacularly failed to produce an alternate evolutionary mechanism even in the lab.

The best 'creationist' comment that I have been made aware of came from a scientist in the mid-west USA who also had religious leanings. When asked by Richard Dawkins, (on camera - BBC I think), how a man of science could possibly argue against the case for evolution, the man said simply... The Ribosome.

Look it up and you'll see why.

Hi Enrique

It may be better to continue this chat on a different thread as it seems to be at odds with the original topic. However, let me just say that none of the tests you mentioned has even conceptually addressed the requirements of a living cell.

To do that, you first need to accommodate the formation of the RNA / DNA mechanism from chemical building blocks, and neither the hydrothermal vents nor muddy pools seem able to do this.

I only mentioned miracles because some believe life from non-life is a scientific impossibility