U4A1: How are species related?
Students examine how evolutionary biology and the relatedness of species is based upon the accumulation of evidence. They learn how interpretations of evidence can change in the light of new evidence as a result of technological advances, particularly in molecular biology. The human fossil record is explored to identify the major biological and cognitive trends that have led to a complex interrelationship between biology and culture.
Heredity (SAC)
- Date: Thursday August 23th (3:30pm - 5:00pm)
- Format: Multiple choice and short answers questions
- Value toward Unit 4 SAC: 50%
- Aim: On completion of this unit the student should be able to analyse evidence for evolutionary change, explain how relatedness between species is determined, and elaborate on the consequences of biological change in human evolution.
Important information about the SAC.
- Here is the checklist
- Here is the practice SAC
- Here is the practice SAC solutions
- To achieve this outcome the student will draw on key knowledge outlined in Area of Study 1, and key skills listed on page 10 & 11 of the Biology Study Design (2013-2016).
GOOGLE DRIVE
Key knowledge
Changes in the genetic makeup of a population
- the qualitative treatment of the causes of changing allele frequencies in a population’s gene pool including types of mutations (point, frameshift, block) as a source of new alleles, chromosomal abnormalities (aneuploidy and polyploidy), environmental selection pressures on phenotypes as the mechanism for natural selection, gene flow, and genetic drift (bottleneck and founder effects) and the biological consequences of such changes in terms of increased or reduced genetic diversity
- processes of evolution including through the action of mutations and different selection pressures on a fragmented population and subsequent isolating mechanisms (allopatric speciation) that prevent gene flow
- the manipulation of gene pools through selective breeding programs.
- significant changes in life forms in Earth’s geological history including the rise of multicellular organisms, animals on land, the first flowering plants and mammals
- evidence of biological change over time including from palaeontology (the fossil record, the relative and absolute dating of fossils, types of fossils and the steps in fossilisation), biogeography, developmental biology and structural morphology
- patterns of biological change over geological time including divergent evolution, convergent evolution and mass extinctions.
- molecular homology as evidence of relatedness between species including DNA and amino acid sequences, mtDNA (the molecular clock) and the DNA hybridisation technique
- the use of phylogenetic trees to show relatedness between species
- the evolution of novel phenotypes arising from chance events within genomes, specifically sets of genes that regulate developmental processes and lead to changes in the expression of a few master genes found across the animal phyla, as demonstrated by the expression of gene BMP4 in beak formation of the Galapagos finches and jaw formation of cichlid fish in Africa.
- shared characteristics that define primates, hominoids and hominins
- major trends in hominin evolution from the genus Australopithecus to the genus Homo including structural, functional and cognitive changes and the consequences for cultural evolution
- the human fossil record as an example of a classification scheme that is open to interpretations that are contested, refined or replaced when new evidence challenges them or when a new model has greater explanatory power, including whether Homo sapiens and Homo neanderthalensis interbred and the placement of Homo denisovans into the Homo evolutionary tree.
Video Resources
