Question

Use the theory of evolution by natural selection to explain how H. pylori bacteria could have evolved to produce urease. (4 Marks)

Answer 1

Answer:

Humans have been colonized by Helicobacter pylori for at least 50,000 years and probably throughout their evolution. H. pylori has adapted to humans, colonizing children and persisting throughout life. Most strains possess factors that subtly modulate the host environment, increasing the risk of peptic ulceration, gastric adenocarcinoma, and possibly other diseases. H. pylori genes encoding these and other factors rapidly evolve through mutation and recombination, changing the bacteria-host interaction. Although immune and physiologic responses to H. pylori also contribute to pathogenesis, humans have evolved in concert with the bacterium, and its recent absence throughout the life of many individuals has led to new human physiological changes. These may have contributed to recent increases in esophageal adenocarcinoma and, more speculatively, other modern diseases.

Answer 2

Helicobacter Pylori have evolved to produce the enzyme urease to counteract the gastric acids and survive in the acidic media of our gastrointestinal system.

• This capability has ensured the longevity of the bacterium. The ability of the bacteria can be explained by the theory of natural selection. This states that certain organisms of a species tend to develop unique abilities.
• A handful of these abilities benefit the survival of the collective species and are more likely to be propagated to the next generation than those traits that prove harmful to the population
• One such trait is the production of urease by the H. pylori bacteria
• This enzyme breaks down urea and turns its immediate surroundings basic, helping it thrive in the stomach of its hosts

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