```ruby
class TaxonAncestor < ActiveRecord::Base
  # attr_accessible :title, :body
  belongs_to :parent, :class_name => "Taxon"
  belongs_to :child, :class_name => "Taxon"
    
end
```

Make parent_id and child_id assignable
user
```ruby
class TaxonAncestor < ActiveRecord::Base
  attr_accessible :parent_id, :child_id
  belongs_to :parent, :class_name => "Taxon"
  belongs_to :child, :class_name => "Taxon"
    
end
```
assistant