[thret]

Peas famously have been cultivated from a single mutation that does not burst when ripe. They can't reproduce without human intervention.

[quakeguy]

Even when birds or small mammals eat and digest the seeds?

[bluGill]

Peas are the seeds.

There are some plans that need an animal to digest the seed covering, but not all plants have that as part of their reproduction cycle. (I'm not sure what pea's natural cycle was)

[quakeguy]

Thank you for clarifying this.

[thret]

To be clear my knowledge of this topic is limited to that found in 'Guns, Germs, and Steel' by Jared Diamond. I haven't checked his sources.