lecture recording on 11 March 2025 at 11.06.32 AM

Overview of Evolution and Genetics

Shift from biblical explanations to scientific understanding of evolution.
Chapter 18 serves as a bridge: connects genetics and molecular genetics to evolution.

Bioinformatics: combines biology with statistics and computing.
Skills in this area essential for making predictions about treatments and diagnoses.
Genomic diversity: size, number of genes, gene density influence evolutionary studies.
Key point: just because a genomic region lacks known function doesn't mean it's useless; it may have undiscovered roles.

Transposons: segments of DNA that can move around within the genome.
Discovery by Barbara McClintock: identified gene mobility in corn genetics.
Initial skepticism due to the novelty of her findings; recognized later for their importance.
Mechanisms of transposable elements:
- Make copies of themselves and insert elsewhere (copy and paste).
- Cut and reintegrate into different chromosome locations (cut and paste).
Thought to explain non-coding DNA with unknown function.
Consideration of how these elements might aid in evolutionary processes.

SNPs (Single Nucleotide Polymorphisms): variations within the 1% of the genome used in forensic analysis.
Evolution demonstrates similarity in genes across species, as shown in homeobox (Hox) genes widely found in insects, indicating similar developmental mechanisms.
Concepts of gradualism in evolution emphasized through fossil discoveries.

Darwin vs. predecessors:
- Darwin contemporary with Mendel but they had different circles of influence.
- Earlier views saw major changes attributed to catastrophic events (e.g., Cuvier).
- Gradual change concept by Hutton and Lyell laid groundwork for Darwin's theories.
Thomas Malthus' ideas on population growth and resources influenced Darwin’s views on natural selection.

Lamarck's idea: species adapt to their environments over time.
Introduced the inheritance of acquired characteristics, which was later disproven (e.g., rat tail experiment).
His insights on environmental influence on evolution were acknowledged, even though he had flawed theories.

Darwin's background: initially aimed to study medicine, then theology, ultimately becoming a naturalist.
Voyaged on the HMS Beagle, where extensive observations were made, especially in the Galapagos Islands.
Observed unique adaptations in fauna, such as tortoises and finches that varied by island.

After years of research, Darwin published On the Origin of Species, outlining natural selection.
Highlights of Darwin's ideas: species evolve over time due to natural selection and adaptation.
Alfred Russel Wallace independently arrived at similar conclusions, prompting collaboration and co-publication with Darwin.
Highlights importance of thorough evidence in establishing scientific theories.

Evolutionary theory fundamentally changed biological sciences, providing a framework for understanding life's diversity.
The theory remains a cornerstone of biology, influencing ecological studies and genetics.