Biological Evolution 2026

Cumulation of all the slide vocab

Coevolution

When two or more species reciprocally affect the evolution of each other through natural selection.

Pairwise Coevolution

A relationship that involves two species or partners.

Diffuse Coevolution

An relationship that involves more than two species that affect one another.

Symbiosis

An interaction between two diffrent organisms living in close physical association.

Endosymbiosis

A symbiotic relationship where one oganism lives inside the other.

What is this an example of…

To survive, the rosette grass needs the fungus Curvularia protuberata. For the fungus to survive, the Curvularia thermal tolerance virus (CThTV) must be present.

A diffuse three-way mutalism

Mutualism

An ecological interaction in which different individuals, often of separate species, act so as to increase each other’s fitness.

Obligate mutualism

A relationship in which each partner can only survive and reproduce successfully in the presence of the other.

Antagonistic coevolution

An evolutionary relationship in which evolutionary changes in each species decrease the fitness of the other species.

Commensalism

The relationsip benifits one partner but does not benifit or harm the other partner.

Secondary endosymbiosis

A eukaryotic host engulfs another eukaryote and gradually forms an endosymbiotic relationship.

True of False…

It is hypothesised that archarbacterium served as the original host for eukaryotes and the creation of such eukaryotes is caused by an endosymbiotic relationship that led to a cell acquiring a mitochondrion and chloroplast.

True

Explain: Interaction and integration of mitochondia and plastids in the cells…

Most of the original mitochondrial and plastid genes have been transferred to the nuclear genome. As a result of this cytoplasmic organelles are heavily dependent on nuclear genes that import more than 90% of their proteins from the cytoplasm.

What is this an example of….

The amoeboid Paulinella chromatophora has develped an relationship with a cyanobacterium, which evolved independently into a plastid organelle (chromatophore).

This is an example of an endosymbiotic relationship

True of False…

Fast evolutionary change tends to be associated with a mutualistic lifestyle.

True

The relationships between the terrestrial ecosystem and mycorrhizae

• Mycorrhizae are present about 80% of land plants

• Fungi provide plants with water, phosphate, and other minerals from the soil, whereas plants provide fungi with carbohydrates produced from photosynthesis.

Cospeciation

The speciation of one partner leads to the speciation event of the other partner.

• May occure whent he benefits of mutualism of both species are high and the mutualistic relationship has been in place over long periods of evolutionary time.

Antagonistic coevolution includes

• Predator-prey coevolution

• Host-parasite coevolution

Aposematic coloration

Warning coloration that functions to warn predators that a potential prey item is venomous or unpalatable.

Batesian mimicry

When a palatable species resembles an umpalatable species.

Műllerian mimicry

When a unpalatable species that shares a common predator resembles one another.

Mosaic coevolution

When the same two species interact mutualistically in come communities but antagonsistically in others.

Deep coalescence/ Incomplete lineage sorting

Explains the similarities between humans and gorillas

• At some loci, humans may be more similar to gorillas than to chimpanzees. If a polymorphism is maintained in the population from the divergence of gorillas to the divergence of chimpanzees, humans and gorillas can end up sharing a common allele that differs from that in chimpanzees.

• Polymorphisms are more likely to be preserved along short, wide (large population size) branches

Chronogram

Shows the relationship between species and how it related to time.

Multiregional hypothesis

Suggest that hominins left Africa and colonized the rest of the Old World at a single time, nearly 2 million years ago, as Homo ergaster.

• Believed that their origins in geographic sparations have been maintained for 2 million years.

Out-of-Africa hypothesis

Seggest that there were three waves of colonization.

1) Homo ergaster arose in Africa, and subsequently migrated into Europe and Asia

2) Homo heidelbergensis migrated into Europe and Asia where it evolved into Homo neanderthalensis and the Denisovan hominin

3) A specie then migrated into Europe and Asia, replacing the premodern hominins (e.g., Homo erectus and Homo neanderthalensis).

• The differences among non-African human populations cannot predate the most recent migration out of Africa 60,000 years ago, and differences even between African populations cannot date back beyond the origin of Homo sapiens in Africa 200,000–130,000 years ago.