Question

1) What was the hidden mechanism of evolution that Darwin knew nothing about?

2) What specifically changed in the DNA of the dark colored pocket mice?

3) Why do some fruit fly species Not have dark wing spots, even though they have the paint brush gene.

Answer 1

1.

Genetics, or the study of how traits are passed down from parents to offspring, had not been fleshed out yet when Darwin wrote his book On the Origin of Species. It was agreed by most scientists of that time period that offspring did indeed get their physical characteristics from their parents, but how and in what ratios was unclear. This was one of the main arguments opponents of Darwin at the time had against his theory. Darwin could not explain, to the satisfaction of the early anti-evolution crowd, how that inheritance happened.

It wasn’t until the late 1800s and early 1900s that Gregor Mendel did his game-changing work with his pea plants and became known as the “Father of Genetics.” Even though his work was very sound, had mathematical backing and was correct that it took quite some time for anyone to recognize the significance of Mendel’s discovery of the field of genetics.

DNA :-

Since the field of genetics did not exist until the 1900s, scientists of Darwin’s time were not looking for the molecule that carries genetic information from generation to generation. Once the discipline of genetics became more widespread, many people raced to discover just which molecule it was that carried this information. Finally, it was proven that DNA, a relatively simple molecule with only four different building blocks, is indeed the carrier of all genetic information for all life on Earth.

Darwin did not know that DNA would become an important part of his Theory of Evolution. In fact, the subcategory of evolution called microevolution is completely based on DNA and the mechanism of how genetic information is passed down from parents to offspring. The discovery of DNA, its shape, and its building blocks have made it possible to track these changes that accumulate over time to effectively drive evolution.

Evo devo :-

Another piece of the puzzle that lends evidence to the Modern Synthesis of Evolutionary Theory is the branch of developmental biology called Evo-Devo. Darwin was unaware of the similarities among groups of different organisms with how they develop from fertilization through adulthood. This discovery was not apparent until long after many advances in technology were available, such as high-powered microscopes, and in-vitro tests and lab procedures were perfected.

Scientists today can examine and analyze how a single-celled zygote changes based on cues from the DNA and the environment. They are able to track similarities and differences of different species and trace them back to the genetic code in each ova and sperm. Many milestones of development are the same between very different species and point to the idea that there is a common ancestor for living things somewhere on the tree of life.

2.

Fur color is controlled by many genes (4:29). Most genes are identical, but dark and light rock pocket mice differ in one gene (Mc1r; 4:55). Data from Data Set 2 show that a mouse's genotype for the MC1R gene affects their fur color. Mice with two copies of allele 2 have the darkest fur.

3.

The paintbrush gene gives the flies the black wing spots, its weird they both have it because only one expresses the spots, the other has no spots.