Complex sentence: Investment in non-genetic children reduces an individual's ability to invest in itself or its genetic children, without directly bringing reproductive benefits (except as mating effort towards the genetic parent), so evolutionary biologists would not expect organisms to regularly and deliberately care for unrelated offspring.
Split into simpler sentences: Investment in non-genetic children therefore reduces an individual's ability to invest in itself or its genetic children, without directly bringing reproductive benefits. Thus, from an evolutionary biology perspective, one would not expect organisms to regularly and deliberately care for unrelated offspring.