Atherosclerotic Stroke

Certainty Style Key
Hover over keys for definitions:
True   Likely   Speculative
Human Uniqueness Compared to "Great Apes": 
Relative Difference
MOCA Domain: 
MOCA Topic Authors: 

While atherosclerotic stroke affects millions of modern humans, it is unknown how often this disease occurs naturally in wild hominid populations. In a research setting, nonhuman primates are used in models of induced stroke in a background of chronic atherosclerosis and captive hominids are known to die of atherosclerotic disease, but atherosclerotic stroke appears to be a relatively unnatural event in wild hominid species. Two species of New World monkey (Lagothrix lagotricha and Aotus sp) display naturally ocurring hypertension and have a higher prevalence of stroke, although the evolutionary mechanisms or relation to human uniqueness for these findings have not yet been speculated.

Hypertension and hyperlipidemia are reliable predictors of atherosclerotic stroke. Both humans and chimpanzees are affected by hypertension, and hyperlipidemia occurs in captive chimpanzees and gorillas; however, atherosclerotic stroke is not associated with coronary heart disease or atherosclerosis in nonhuman primates. Thus it is speculated that while nonhuman primates experience atherosclerotic stroke naturally, it occurs to a lesser degree than in humans.

The difference in susceptibility between humans and hominids is less likely to be due to genetic differences
since the genetic profile of human and chimpanzee hearts and livers (the main organs for atherosclerotic disease) are nearly identical. Genetic differences may explain differences in atherosclerotic stroke prevalence. In the prevailing theory, humans may have lost genes which enable adaptive traits, but which also cause a retrograde phenotype that increases susceptibility to atherosclerotic disease. In a less supported theory, humans may have recently acquired a gene that increases risk for atherosclerotic disease.

Given the ability to induce atherosclerosis in nonhuman primates; differences in atherosclerotic disease prevalence may significantly impacted by a modern high fat, high salt human diet which is shown to cause hyperlipidemia and hypertension in hominin species (precursors to atherosclerosis and thus increased susceptibility for stroke).

Timing

Timing of appearance of the difference in the Hominin Lineage as a defined date or a lineage separation event. The point in time associated with lineage separation events may change in the future as the scientific community agrees upon better time estimates. Lineage separation events are defined in 2017 as:

  • the Last Common Ancestor (LCA) of humans and old world monkeys was 25,000 - 30,000 thousand (25 - 30 million) years ago
  • the Last Common Ancestor (LCA) of humans and chimpanzees was 6,000 - 8,000 thousand (6 - 8 million) years ago
  • the emergence of the genus Homo was 2,000 thousand (2 million) years ago
  • the Last Common Ancestor (LCA) of humans and neanderthals was 500 thousand years ago
  • the common ancestor of modern humans was 100 - 300 thousand years ago

Possible Appearance: 
6,000 thousand years ago
Probable Appearance: 
2,000 thousand years ago
Definite Appearance: 
100 thousand years ago
Related MOCA Topics
Related Topics (hover over title for reason):

References

  1. Heart disease and stroke statistics--2012 update: a report from the American Heart Association., Roger, Véronique L., Go Alan S., Lloyd-Jones Donald M., Benjamin Emelia J., Berry Jarett D., Borden William B., Bravata Dawn M., Dai Shifan, Ford Earl S., Fox Caroline S., et al. , Circulation, 2012 Jan 3, Volume 125, Issue 1, p.e2-e220, (2012)
  2. Different strokes for different folks: the rich diversity of animal models of focal cerebral ischemia., Howells, David W., Porritt Michelle J., Rewell Sarah S. J., O'Collins Victoria, Sena Emily S., H van der Worp Bart, Traystman Richard J., and Macleod Malcolm R. , J Cereb Blood Flow Metab, 2010 Aug, Volume 30, Issue 8, p.1412-31, (2010)
  3. Human and Chimpanzee Gene Expression Differences Replicated in Mice Fed Different Diets, Somel, M., Creely H., Franz H., Mueller U., and Lachmann M. , PLoS ONE, Volume 3, Issue 1, (2008)
  4. Naturally occurring hypertension in New World nonhuman primates: Potential role of the perifornical hypothalamus., Smith, Orville A., and Astley Cliff A. , Am J Physiol Regul Integr Comp Physiol, 2007 Feb, Volume 292, Issue 2, p.R937-45, (2007)
  5. Occurrence of stroke in a nonhuman primate model of cerebrovascular disease., Prusty, S, Kemper T, Moss M B., and Hollander W , Stroke, 1988 Jan, Volume 19, Issue 1, p.84-90, (1988)