How Evolution Works, Part 1

[stardust]

One way to understand Evolution is to first understand “Artificial Selection”. Wolves and Dogs are descended from common ancestors (which looked more like modern wolfs than dogs). Over many generations, Humans selected the “favourable” traits (e.g., long shiny fur, or stocky legs etc) to produce the many different types / breeds of modern dogs that we have today. The keyword here is “over many generations”. There are modern dogs that, of course, are still very much wolve-like in appearance (e.g., Huskies, German Shepherd etc). Some dog breeds are much less wolf-like in appearance (Chihuahua, Shih Tzu etc) as they have been artificially selected for their small size and “cute” traits. So why is it known as artificial selection? This is because the Human (the dog breeders) are the ones determining which individual dogs they would prefer to produce offsprings, thereby continuing the genes they would like to retain. Prior to this, it is also important to understand the idea of Variation. This means that in a litter of puppies, not every puppy is physically identical (even though they may look identical to the untrained eyes). Some puppies have slightly longer legs, some shorter legs. Very small differences, but, yes, the differences are there. It is due to this physical variations that the breeders (humans) select which dogs possess the traits he wants, thus the term “Artificial Selection”. This Selection process is repeated over many generations and the result is the modern dog breeds we have today.

Once we understood Artificial Selection, it will be easy to understand Natural Selection. In Natural Selection, the environment aka Mother Nature (instead of Human) is the factor deciding which traits survive through the generations. How? One example is Food Source. Many species of birds have developed the ability to swim to obtain their food (Adaptability). One pre-requisite of aquatic birds is having water-proof feathers. In this case, this is the “Favourable Trait”. One group of birds may live nearer to the seasides and Individual birds with better waterproof feathers is seen by Mother Nature as a “favourable trait”. And so individual birds with this trait has a much higher chance of survival and passing on this gene to the next generations. Birds with “less waterproof” feathers may probably not even live to adulthood as they had difficulties obtaining their food (in the sea), resulting in their genes being eliminated from this group of birds. Using an analogy, you may think of this process as a kind of filtration process, where only the finest particles is able to pass through the fine filter. This is Adaptation, and it has to be highlighted that Adaptation takes place over many, many, many generations. Physical Adaptations (e.g., change in body shapes) DO NOT take place in just one generation. In other words, an individual animal will not change its form physically to obtain that trait in its lifetime, unless it’s metamorphosis which is a totally different thing.

We also observed this in rabbits living in deserts and rabbits living in cold countries. The long ears in rabbits act as effective heat radiators. This enables the rabbits to lose body heat efficiently, just as how humans lose heat efficiently by sweating. The rabbits living in deserts adapted (over many generations) to the environment by developing very long and erect ears for highly efficient lowering of their body temperature. But rabbits living in cold countries tends to have shorter ears (some even have lop ears). Shorter ears is the “favourable trait” here as it enables them to lose less body heat. All animals (and yes, that includes Humans) are still in the midst of Evolution. If Evolution is constantly ongoing, why can’t we see it happening? We need to understand that Evolution is a very, very slow on-going process. Evolution will never be “complete”, as change is the only constant. If Evolution is true, why are there no animals that are “neither here nor there” (i.e., in-between two species)? We need to remember humans are the ones who gave distinct names to different distinct species of animals in the first place. Let us look at the Seals / Walruses. Their ancestors are land animals, but their body shapes (flippers and hydrodynamic bodies) are hard evidence that they are in the midst of “transition” from land animals to aquatic animals, as their main source of food is in the sea. Of course, we cannot see an appreciable change in their appearances in our lifetime, as the change is happening far too slowly over many generations. So presently, we can only imagine the current physical appearances of Seals / Walruses as being “frozen-in-time”, as with the rest of the millions of species of animals currently living on this planet Earth. And do appreciate their beauty in their current physical form (and the diversity of the Tree of Life), as they will never be the same again one million years from now.

[drewstillexists]

Wow, it's a shame these comments are filled with people who are willfully ignorant. Keep it up, BioLogos. Encourage Christians to not be crazy.

[vincentandrews]

Job 38:4 - Where were you when I laid the foundations of the earth? Tell Me,  if you have understanding.

Colossians 2:8 - See to it that no one takes you captive by philosophy and empty deceit, according to human tradition, according to the elemental spirits of the world, and not according to Christ.

Exodus 20:11 - For in six days the Lord made heaven and earth, the sea, and all that in them is, and rested the seventh day: wherefore the Lord blessed the sabbath day, and hallowed it.

John 5:46-47 - For had ye believed Moses, ye would have believed me; for he wrote of me. But if ye believe not his writings, how shall ye believe my words?

Proverbs 30:6 - Do not add to His words or He will reprove you, and you will be proved a liar.

[grimadean]

Here's my question: Are you saying that God set up a process in which organisms evolve that allow them to produce previously unknown genetic information; Or are you saying that God inserts new, unique genetic information directly to cause evolution rather than using an evolutionary process?

[TheMickeymental]

Abiogenesis is not possible deeming evolution is not possible. It is called cause and effect children. I know these two processes are separate, so what, it is called logic children.

[manojmani]

Hi there, can I upload this video on my Facebook page?

[fnanfne]

Is the concept explained at around 1:20 known as "Convergent Evolution"?

[FreeKentHovind]

Evolution is a fairy tale for grownups.
Now variations happen within different animals kinds - but they're limited.