EVOLUTION AND GENETICS COME TOGETHER

Question 1

What were the questions that arose about darwinism?

Answer 1

1. Wont new variants be swamped and disappear before natural selection could occur?
2. All new genetic variations deleterious as it appeared so, then where did adaptive variants come from and how could natural selection be a creative force leading to newer generation being more adaptive than old ones
3. Arent the Earth and Sun too young to account for such slow process of natural selection
4. Why do fossils seem to form a progressive series from lower to higher layers even if natural selection has no directionality
5. Why are there gaps and jumps in fossil records? - change should be incremental and not transitional

Question 2

What was Hogo De Vries Mutation Theory?

Answer 2

Hugo de Vries’ Mutation Theory suggested that new species could suddenly arise through rare and significant genetic mutations, challenging the prevailing idea of gradual evolution. His study of the evening primrose provided initial evidence for these ideas, impacting how scientists understand the role of mutations in evolutionary processes. Unlike Darwin’s theory, which emphasized gradual, continuous variation, de Vries argued for discontinuous, saltational changes (jumps).

Question 3

How did Vries Theory answered the ques on darwinian theory

Answer 3

Swamping of New Variants: Explained how new traits could appear and persist despite being diluted in a large population.

Selection Creative: Showed how new traits could provide material for natural selection.

Fossils in a Progressive Series: Suggested that sudden changes could explain the appearance of new species in different layers.

Young Earth: Suggested that large, sudden changes could happen quickly, fitting within a shorter timeline.

Gaps in the Fossil Record: Explained by sudden jumps, leaving fewer intermediate forms.

Question 4

What was the issue with Vries experimentation?

Answer 4

The unique nature of the plant - uncommon mutation patterns so cannot conclude the same for all plants

Question 5

What is another example of saltational evolution?

Answer 5

Richarf godschimdt : microevolution does not lead to macroevolution we need large genetic jumps to explain speciation

Question 6

What is orthogenesis?

Answer 6

It was an evolution theory that stated evo to be following a pre-determined approach displaying linearity towards a certain goal. It is not random and is guided by both internal and external factors

Question 7

What were other models of evolution

Answer 7

Orthogenesis and Neo-Lamarckism

Question 8

What is Neo-Lamarckism

Answer 8

Organisms can inherit characteristics or traits acquired by parents through lifetime along with genetic inheritance. It is not widely accepted as it lacks empirical evidence and acquiring traits is limited and negligible in most cases

Question 9

Who proposed the populational approach to Mendelian characteristics?

Answer 9

Hardy and Weinberg

Question 9

WHat was the populational approach to Mendelian genetics?

Answer 9

• how do gene frequencies remain stable in a population over time
• they focused on Mendelian factors: how traits are inherited from parents to offspring through genes
• formulated a mathematical principle that states gene frequencies will remain constant in a population if certain conditions are met.
  These conditions include no mutations, no natural selection, no migration, large population size, and random mating.
• helped scientists understand how genetic variation is maintained and how traits can appear or disappear over time
• a way to predict how common certain traits will be in a group of animals or plants over many years. They used math to show how genes stay the same or change in groups of animals or plants.

Question 10

What was soviet evolutionary biology and genetics good at?

Answer 10

Agricultural genetics and genetic variations in natural populations

Question 11

what is the modern synthesis?

Answer 11

The modern synthesis, also known as the neo-Darwinian synthesis, was a major advancement in biology that combined Darwin’s theory of evolution with Mendelian genetics. It combined darwins idea about how species change with Mendel’s genetics to explain how traits are passed down

Question 12

How are principles of new genetics sufficient to explain Darwinian evolution?

Answer 12

1. no inheritance of acquired traits
2. Mutation - changes in the genes provide raw material for evolution
3. Persistence of recessive traits throughout the generations despite sexual reproduction
4. Recombination - during reproduction genes from parents can mix and create new combinations of traits
5. Gene Interactions: Genes can work together to influence traits, affecting how organisms survive and reproduce.
6. Particulate inheritance
7. No blending inheritance implying traits remain distinct at the genetic level

Question 13

What other factors contribute to the modern synthesis?

Answer 13

1. Importance of selection - natural selection doesn’t need to be strong to have an impact on evolution even small changes in traits can impact ability to survive and reproduce
2. Enlarged the set of causes for evolution - MS expanded our understanding of what drives evolution. t included factors like mutations, genetic drift (random changes in gene frequencies), and gene flow (migration of genes between populations).
3. No barrier b/w micro and macro evo : he synthesis argued that there’s no strict division between small changes (microevolution) and large-scale changes (macroevolution).
   Example: Over time, small changes (like variations in beak size in birds) can accumulate into larger changes (like different species of birds with different beak shapes).