evo bio CH 21-Human Evolution

• Hominoids are a superfamily of primates that are characterized by certain anatomical features, such as large brains, forward-facing eyes, and the ability to walk upright on two legs (bipedalism).


  hominoids represent a diverse group of primates that includes humans, great apes, and lesser apes
• Coalescence


  the process by which genetic lineages in a population come together or coalesce as they trace their ancestry back in time. It involves identifying the point in the past where two or more genetic lineages converge to a single common ancestor.
• Hominoidea

  a taxonomic grouping that comprises apes, which are characterized by features such as large brains, lack of tails, and the ability to grasp objects with their hands (prehensile hands).

  This superfamily is further divided into two families: Hominidae (great apes) and Hylobatidae (lesser apes).
• Hominidae

  a taxonomic family that comprises great apes, including humans, chimpanzees, gorillas, and orangutans.

  Members of the Hominidae family are characterized by features such as large brains, complex social behaviors, and the absence of a tail.
• Hominid modifications

  • Reason = change in ecology

  • Cooling

  • Shift from tropical forest to savannah
• The spread of humans

  • Good agreement on African origin

  • Two models for spread

  • Multiregional
  • Out of Africa
• Multiregional Hypothesis


  theory that suggests modern humans (Homo sapiens) originated from multiple regional populations of archaic humans, such as Homo erectus, rather than from a single population in a specific location.
• Out of Africa Hypothesis


  also known as the Replacement Hypothesis, is a theory that suggests modern humans (Homo sapiens) originated from a single population in Africa and later dispersed to populate the rest of the world, replacing other archaic human populations.
• the human microbiome is an integral component of human biology that has co-evolved with humans and influenced various aspects of human health and evolution
• relatives of Homo sapiens

  1. H. heidelbergensis

  • denisovan hominins
  • H. neanderthalensis

  2. H. ergaster

  3. H. erectus
• allopatric speciation


  when a population splits into two or more species due to geographic isolation