4.5.4 Evolutionary Relationships

Molecular Phylogeny

• Molecular phylogeny involves studying the DNA, RNA, and proteins of organisms to determine their evolutionary relationships.
• It helps identify shared ancestry by comparing molecular structures.

Three Domains

Findings from molecular phylogeny led to the classification of all organisms into three main domains:

1. Bacteria – Prokaryotic cells with no membrane-bound organelles.
2. Archaea – Prokaryotic cells with distinct molecular features separating them from bacteria.
3. Eukaryota – Organisms with eukaryotic cells, including plants, animals, fungi, and protists.

Scientific Validation of Evolutionary Data

When new evolutionary relationships are proposed, the scientific community ensures the validity of the data through:

4. Publication in Peer-Reviewed Journals:

• Scientists present their findings for evaluation by others in the field.
• Peer review ensures the research is credible and accurate.

5. Scientific Conferences:

• Findings are shared and discussed at conferences to gain feedback from other scientists.

6. Independent Testing:

• Other scientists collect evidence to either support or challenge the conclusions.

7. Consensus Development:

• After extensive scrutiny and testing, the scientific community may accept the proposed relationships.