EVO lecture 1

Evolutionary history of mammals

Mammals descended from the Cretaceous, all had hair and produced milk.

Monotremata

Mammals that lay eggs, such as the platypus.

Taxons in phylogeny

Different lineages, with more recent species at the top and the last common ancestor at the bottom.

Branching events in phylogeny

Called nodes.

Determining evolutionary relationships

Through ribosomal DNA sequences, which reconstruct phylogeny.

Domains in phylogeny

Bacteria, archaea, and eukarya.

Human origin

Humans originated from Africa.

Human dispersal

Humans spread out 65,000 years ago and crossed the Bering Strait around 16,000 years ago.

Environmental adaptations

Malaria led to adaptations for resistance, while cold regions led to adaptations for survival in low temperatures.

First fundamental observation of evolution

All biological diversity is grouped into a hierarchical system of classification (KFCOFGS), and no species is truly unique.

Species change over time

Yes, all species change over time. Example: Trilobites showed changes in rib structure over time.

Punctuated change in evolution

A sudden change in species, like the morphological changes observed in stickleback fish.

Antibiotic resistance evolution

Strains like Methicillin-resistant Staphylococcus aureus (MRSA) have increased in resistance over time.

COVID-19 adaptations

COVID-19 kept mutating and developing new strains, adapting to the human environment.

Complexity of life's origin

Descendant lineages are modifications of beginning lineages, which leads to simpler forms first.

Adaptation in evolutionary biology

A good fit between an organism and the environment it lives in.

Crypsis

The ability of an organism to hide from predators.

Vestigial genes (pseudogenes)

Imperfect copies of a functional gene that have lost some or all functionality, like the human vitamin C gene.

Suboptimal design in biology

A design that is not perfectly optimized, such as the human airway conflicting with the food pathway.

Key elements of the evolutionary explanation

1. Change over time 2. Descent with modification 3. Evolution by natural selection.

Evolution definition

Both an observable fact and a complex theory explaining biological changes over time.

Importance of evolutionary biology

It provides scientific explanations for the origin of life and can be used to solve various biological problems.