user-1: I think the interesting part is to first classify archaic humans, as a manussa or a tiracchāna?
Is there any explanation about this? Since as far as I know, Buddhism supports the theory of evolution.

user-1: There are times when humans hold long lifespan, good conducts, beautiful and large bodies, and there are times when their lifespans are short, bad, animal-like conducts, ugly small bodies. Currently it goes foward the decaying line again. Lifespan, bodies, without much taken support, is already very short and degenerated. So the age of going into relationship.
(Note that this gift of Dhamma is not dedicated for trade, exchange, stacks or entertainment but as a means to make merits toward release from this wheel)

user8157: The word tiracchāna means "going crosswise or obliquely or horizontally". It probably means to mentally not go beyond the instinctual existence of enslavement to instinctual desires. It appears to not have the biological meaning of having four legs. Since the theory of evolution is biological, it is unrelated to Buddhism, which is psychological. 
People who are "territorial", engage in unthoughtful breeding or reproduction, who are ruled by their emotions & instinctual drives, who cannot discern the future consequences of their actions, etc, are tiracchāna. Their life goes "crosswise or obliquely or horizontally" because they do not "transcend/go beyond the common level" ("vītivatto puthujjanabhūmiṃ"). They don't go "upward". They go "horizontally". 
For example, the lives of four-legged animals have no significant purpose. The lives of four-legged animals is the same, generation after generation after generation. All they do is reproduce, look for food and fight to protect their territory and protect their life from predators. People who live like this are "tiracchāna" or "going horizontally".  
"Tiracchāna" are the "groundlings" that "crawl" rather than "climb" ("āruyha"). 

28. Just as one upon the summit of a mountain beholds the groundlings (bhummaṭṭha), even so when the wise man casts away heedlessness by
  heedfulness and ascends/climbs (āruyha) the high tower of wisdom, this sorrowless sage
  beholds the sorrowing and foolish multitude.
Dhammapada


-1: <p>I think the interesting part is to first classify archaic humans, as a manussa or a tiracchāna?</p>

<p>Is there any explanation about this? Since as far as I know, Buddhism supports the theory of evolution.</p>
 -1: <p>There are times when humans hold long lifespan, good conducts, beautiful and large bodies, and there are times when their lifespans are short, bad, animal-like conducts, ugly small bodies. Currently it goes foward the decaying line again. Lifespan, bodies, without much taken support, is already very short and degenerated. So the age of going into relationship.</p>

<p><em>(Note that this gift of Dhamma is not dedicated for trade, exchange, stacks or entertainment but as a means to make merits toward release from this wheel)</em></p>
 8157: <p>The word <a href="https://suttacentral.net/define/tiracch%C4%81na" rel="nofollow noreferrer">tiracchāna</a> means "<em>going crosswise or obliquely or horizontally</em>". It probably means to <em>mentally</em> not go beyond the instinctual existence of enslavement to instinctual desires. It appears to not have the biological meaning of having four legs. Since the theory of evolution is biological, it is unrelated to Buddhism, which is psychological. </p>

<p>People who are "territorial", engage in unthoughtful breeding or reproduction, who are ruled by their emotions &amp; instinctual drives, who cannot discern the future consequences of their actions, etc, are tiracchāna. Their life goes "<em>crosswise or obliquely or horizontally</em>" because they do not "<em>transcend/go beyond the common level</em>" ("<em>vītivatto puthujjanabhūmiṃ</em>"). They don't go "upward". They go "horizontally". </p>

<p>For example, the lives of four-legged animals have no significant purpose. The lives of four-legged animals is the same, generation after generation after generation. All they do is reproduce, look for food and fight to protect their territory and protect their life from predators. People who live like this are "tiracchāna" or "going horizontally".  </p>

<p>"Tiracchāna" are the "groundlings" that "crawl" rather than "climb" ("āruyha"). </p>

<blockquote>
  <p><em>28. Just as one upon the summit of a mountain beholds the groundlings (bhummaṭṭha), even so when the wise man casts away heedlessness by
  heedfulness and ascends/climbs (āruyha) the high tower of wisdom, this sorrowless sage
  beholds the sorrowing and foolish multitude.</em></p>
  
  <p><em>Dhammapada</em></p>
</blockquote>
